It used to be that t_addrmode_s4 was used for both:

o A8.6.195 STR (register) -- Encoding T1
o A8.6.193 STR (immediate, Thumb) -- Encoding T1

It has been changed so that now they use different addressing modes
and thus different MC representation (Operand Infos).  Modify the
disassembler to reflect the change, and add relevant tests.

llvm-svn: 127833

2 files changed, 22 insertions, 16 deletions

diff --git a/llvm/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h b/llvm/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
index 33889da77d6..fcfe1de17a4 100644
--- a/llvm/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
+++ b/llvm/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
@@ -598,7 +598,7 @@ static bool DisassembleThumb2Ldpci(MCInst &MI, unsigned Opcode,
 
 // A6.2.4 Load/store single data item
 //
-// Load/Store Register (reg|imm):      tRd tRn imm5 tRm
+// Load/Store Register (reg|imm):      tRd tRn imm5|tRm
 // Load Register Signed Byte|Halfword: tRd tRn tRm
 static bool DisassembleThumb1LdSt(unsigned opA, MCInst &MI, unsigned Opcode,
     uint32_t insn, unsigned short NumOps, unsigned &NumOpsAdded, BO B) {
@@ -624,28 +624,25 @@ static bool DisassembleThumb1LdSt(unsigned opA, MCInst &MI, unsigned Opcode,
                                                      getT1tRn(insn))));
   OpIdx = 2;
 
-  // We have either { imm5, tRm } or { tRm } remaining.
-  // Process the imm5 first.  Note that STR/LDR (register) should skip the imm5
-  // offset operand for t_addrmode_s[1|2|4].
+  // We have either { imm5 } or { tRm } remaining.
+  // Note that STR/LDR (register) should skip the imm5 offset operand for
+  // t_addrmode_s[1|2|4].
 
   assert(OpIdx < NumOps && "More operands expected");
 
   if (OpInfo[OpIdx].RegClass < 0 && !OpInfo[OpIdx].isPredicate() &&
       !OpInfo[OpIdx].isOptionalDef()) {
-
-    MI.addOperand(MCOperand::CreateImm(Imm5 ? getT1Imm5(insn) : 0));
+    assert(Imm5 && "Immediate operand expected for this opcode");
+    MI.addOperand(MCOperand::CreateImm(getT1Imm5(insn)));
+    ++OpIdx;
+  } else {
+    // The next reg operand is tRm, the offset.
+    assert(OpIdx < NumOps && OpInfo[OpIdx].RegClass == ARM::tGPRRegClassID
+           && "Thumb reg operand expected");
+    MI.addOperand(MCOperand::CreateReg(getRegisterEnum(B, ARM::tGPRRegClassID,
+                                                       getT1tRm(insn))));
     ++OpIdx;
   }
-
-  // The next reg operand is tRm, the offset.
-  assert(OpIdx < NumOps && OpInfo[OpIdx].RegClass == ARM::tGPRRegClassID
-         && "Thumb reg operand expected");
-  MI.addOperand(MCOperand::CreateReg(
-                  Imm5 ? 0
-                       : getRegisterEnum(B, ARM::tGPRRegClassID,
-                                         getT1tRm(insn))));
-  ++OpIdx;
-
   return true;
 }
 
diff --git a/llvm/test/MC/Disassembler/ARM/thumb-tests.txt b/llvm/test/MC/Disassembler/ARM/thumb-tests.txt
index 36f74381a5e..26a6af8404a 100644
--- a/llvm/test/MC/Disassembler/ARM/thumb-tests.txt
+++ b/llvm/test/MC/Disassembler/ARM/thumb-tests.txt
@@ -27,6 +27,15 @@
 # CHECK:	ldmia	r0!, {r1}
 0x02 0xc8
 
+# CHECK:	str	r0, [r3]
+0x18 0x60
+
+# CHECK:	str	r0, [r3, #4]
+0x58 0x60
+
+# CHECK:	str	r2, [r5, r3]
+0xea 0x50
+
 # CHECK:	ldrb.w	r8, #-24
 0x1f 0xf8 0x18 0x80